Conductor for electric wires



(No Model.)

J. GRANT.

OONDUGTOR POE ELECTRIC WIRES. No. 371,681. Patented Oct. 18, 1887.

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UNITED STATES PATENT OFFICE,

JOHN GRANT, OF OMAHA, NEBRASKA.

CONDUCTOR FOR ELECTRIC WIRES.

SPECIFICATION forming part of Letters Patent No. 371.681, dated October 18, 1887.

Application tiled February 19, 1887. Serial No. 228,245. (No model.)

To all whom it may concern:

Be it known that I, JOHN GRANT, a citizen of the United States, residing at Omaha, in the county of Douglas, State of Nebraska, have invented certain new and useful Improvements in Underground Electric Conductors,of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to certain improvements in underground electric conductorsgand it has for its Objects, first, to provide an improved insulating compound for covering such conductors which will effectually exclude moisture and the leakage of thel current consequent thereupon, which will be pliable and, to a certain extent, elastic, so as to bend with the wires withoutbreaking, which will expand and Contract with 'the wires, and which will be comparatively -indestructible under the conditions and uses to which it is applied; second, to provide au insulating material which may be readily applied to one or any series of wires as they are laid and stretched in their underground beds,so as to effect perfect insulation, as more fully hereinafter set forth, and, third, to provide improved means for laying the wires in the insulating compound, as more fully hereinafter specied.

My invention consists in a composition of rosin with certain petroleum products-such as dead-oil, or the Caput mortuum, or the comparatively useless portions left after refining crude petroleum-and in some instances with paraftine and naphthaline, the said products being designed to modify the character of the rosin, so as to destroy its brittleness, increase its tenacity, and enhance its insulating properties, by preventing` cracking and the infiltration of moisture which would be attendant thereupon.

In the accompanying drawings, Figure 1 represents a perspective view showing my improved conduit in course of construction; and Fig. 2, a detached view of one of the sheets, showing the wires partially embedded therein.

In carrying out my invention I lrst melt the rosin in any desiredquantity and in any convenient vessel, and then add the oil thereto in proper proportion to give the ultimate compound the requisite characteristics.

The oil I employ is preferably the dead-oil resulting from the distillation of petroleum, although other petroleum products-such as paraffine-oil, naphthaline, or other like petroleum compounds-*may be employed.

The proportions of the rosin and the oil may vary greatly, according to circumstances; but for general use where the compound consists of rosin and oil exclusively I have found from twelve to twenty per cent. of oil to rosin to answer well for general purposes, and, Where sand, slag, or other silicious or vitreous substance forms partofthe compound, from twenty to thirty per cent. of oil.

The compound may be applied to the wires singly, so as to coat each individually; but I prefer toform the compound into sheets of suitable dimensions for convenience of transportation aud manipulation. Vhere the sheets are employed,a continuous layer or base of the same is laid in the underground trench and the wires stretchedalong its surface at properly-spaced intervals. Over the wires, when thus laid, a similar layer is superposed and compressed against the lowerlayer,embedding the wires between the layers, the nature of the compound being such that the respective sheets coalesce at their junctions, forming impervious and perfectly-insulated coverings for the wires. In some instances the wires may be initially laid in suitable troughs or on forms temporarily laid in the trench, and the compound run in in a fluid state, and after hardening or setting the trough or forms may be removed, leaving the compound to support the wires alone as well as insulate them. The joints between the sheets,when the same are laid, may loe filled with the fluid cement and thus hermetically sealed, but this will be unnecessary ordinarily, as the nature of the cement will close the joints, generally, without this extra precaution. Asa matter of course, in either case of laying and applying the wires, the trenches after the conduit has been laid are covered up and paved over in the usual manner.

Having thus fully described my invention,

what I claim, and desire to secure by Letters In testimony whereof I affix my signature in Patent, ispresence of two witnesses.

The compound herein described for insuleting electric conductors, the same consisting JOHN GRANT' 5 of rosin and petroleum residuum thoroughly Witnesses:

mixed, so as to form a semiplastic mass, sub- CHAs. HELM,

lstentially as described.

GHAs. L.A CooMBs. 

